The use of inflatable cushions for packaging goods has been known in the packaging art for some time, although not heretofore widely used commercially in the packaging industry. U.S. Pat. No. 3,521,743, issued on Jul. 28, 1970 to Carlo J. Sposito, Jr. for "Cushion Package", for example, discloses an inflation packaging system comprising two air cushions. Likewise, U.S. Pat. No. 4,905,835, issued on Mar. 6, 1990 to Alain Pivert and Michael L. Pezzo for "Inflatable Cushion Packaging" also employs two separate inflatable structures used to package articles. One commercially available inflatable envelope device, called "Airtex", is manufactured by Air Packaging Technologies in Valencia, Calif., referencing U.S. Pat. Nos. 4,874,093 4,872,558 and 4,918,904.
In packaging articles between inflated cushions, in outer boxes, it is advisable that both cushion air chambers be isolated from one another. In a package where air communication is permitted between air cushions, protecting an article, as in the "Airbox" envelope, in which the chambers communicate through a hole, after the package is maintained in the same position for some time, the pressure gradient between cushions, caused by the weight of the article on one cushion, is equalized by the deflation of the support cushion and the inflation of the top cushion; the article thus being displaced downward towards the outer box wall, particularly for relatively heavy articles. Thus, the use of two isolated chambers is preferentially necessary to prevent air passage from one chamber to another and thus maintain the position of the article.
Some of the prior arc has accomplished this function of maintaining two separate air chambers by employing two distinct cushioning members that can be inflated either separately or simultaneously with tubing systems incorporating valves. The costs associated with the use of two distinct cushioning members, tubing, and valves, has, to date, however, proved too expensive for wide-spread use in industry.
The present invention is accordingly directed to the solution of the problem of providing an inexpensive inflation cushioning system that comprises at least two air chambers that can be filled simultaneously without the use of special tubing or valves, and that can then be independently sealed, the structure being readily formed, at low cost, from a single flat bag envelope, while minimizing the volume of required material.